403640641 has 4 divisors (see below), whose sum is σ = 404387284. Its totient is φ = 402894000.

The previous prime is 403640621. The next prime is 403640651. The reversal of 403640641 is 146046304.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 62869041 + 340771600 = 7929^2 + 18460^2 .

It is a cyclic number.

It is not a de Polignac number, because 403640641 - 2⁷ = 403640513 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (403640621) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 372510 + ... + 373591.

It is an arithmetic number, because the mean of its divisors is an integer number (101096821).

Almost surely, 2^403640641 is an apocalyptic number.

It is an amenable number.

403640641 is a deficient number, since it is larger than the sum of its proper divisors (746643).

403640641 is an equidigital number, since it uses as much as digits as its factorization.

403640641 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 746642.

The product of its (nonzero) digits is 6912, while the sum is 28.

The square root of 403640641 is about 20090.8098642140. The cubic root of 403640641 is about 739.0349246753.

Adding to 403640641 its reverse (146046304), we get a palindrome (549686945).

The spelling of 403640641 in words is "four hundred three million, six hundred forty thousand, six hundred forty-one".